Comminuting mill with means for lateral injection of fluid thereinto



Jan. 15', 1952 H. KRONSTAD COMMINUTING MILL WITH MEANS FOR LATERALINJECTION OF FLUID THEREINTO 4 Sheets-Sheet 1 Filed Jan. 4. 1949 awe/WmHeme/am Eonxiacl ATTOR N EY Jan. 15, 1952 H. KRONSTAD COMMINUTING MILLWITH MEANS FOR LATERAL INJECTION OF FLUID THEREINTO 4 Sheets-Sheet 2Filed Jan. 4. 1949 ATTO R N EY Jam 1952 H. KRONSTAD COMM'INUTING MILLWITH MEANS FOR LATERAL INJECTION OF FLUID THEREINTO 4 Sheets-Sheet 3Filed Jan. 4. 1949 3 wu Whom jazz/an! fiwzsiad KA/X ATTOR N EY Jan 15,1952 KRN$TAD 2,582,547

COMMINUTING MILL WITH MEANS FOR LATERAL INJECTION OF FLUID THEREINTOFiled Jan. 4. 1949 4 Sheets-Sheet 4 ATTOR N EY Patented Jan. 15, 1952COMMINUTING MILL WITH MEANS FOR LATERAL INJECTION F FLUID THERE- INTOHaavard Kronstad, Mahoningtown, Pa.

Application January 4, 1949, Serial No. 69,227

1 Claim.

This inventionis concernedwith mills for reducing the granular orparticle size ofsolid matter such as rock, ores, material for subsequentconversion into cement clinker, etc., to the desired degree ofcomminution, and it relates particularly to rotary mills that aredivided into a plurality of grinding chambers.

Usually balls, rods, or other loose tumbling elements in the drum ofsuch mills contribute to grinding action.

It is an object of the invention to provide means to force air or otherfluid'in whirling streams into the grinding chambers through the sidewall of the drum, to facilitate grinding action, and also moreeffectively to cool the interior of the mill remote from the feed end.

When considered with the description herein, characteristics of theinvention are apparent in the accompanying drawing, forming part here-01, wherein association of an adaptation of the invention with acylindrical shell ball mill is disclosed.

Like reference-characters refer to corresponding parts in the views ofthe drawing, of which- Fig. 1 is a side elevation of the mill;

Fig. 2 is a plan view thereof;

Fig. 3-is a section on line 3-3, Fig. 4;

Fig. 4 is a section on line 4-4, Fig. 3;

Fig; 5 is a section on line 5--5, Fig. 4;

Fig. 6 is a section on line 6-45, Fig. 3;

Fig. 7 is a section on line 1-1, Fig. 4.

In the drawing, ll designatessupporting pillars on'which are mountedbearings I2, in which rotate a hollow feed trunnion l3 and a hollowdischarge trunnion extending outwardly from end walls l5 and i6,respectively, of a drum having acylindrical outer side wall [1.

A: feed element, as indicated by I8, is associated with the trunnion l3,and a discharge hood l9, discharge pipe 20, and apipe 21 leading to adust collector'are associated with the trunnion l4.

Thedrum is rotated by a gear 22 fast thereon, which is driven by apinion 23, shafting 24, and motor 25.

The drum is lined with longitudinal plates 26 secured to the drum wall,and the plates have longitudinal ribs 21. The interior of the drum isdivided into chambers by a division head 28, which has radial spiderarms or vanes 29. The ribs 2'! contribute to the cascading of materialbeing ground in the mill during its rotation.

Parts of the will thus referred to, which are more or less conventional,are shown as a basis for explaining the present invention, which relatesto association with a mill of this type of means to inject whirlingstreams of fluid'sidewise into one or more of the treating chambersthereof.

The invention provides a continuous bearing surface, or a plurality ofthem, around the circular side of the drum, a passage, beginning in theannulus of the surface or surfaces, extending into the drum, achamber-containing member having a bearing surface in contact with thatof the drum, an opening from the chamber align.- able with the drumpassage, means to prevent rotation of the member, and means to forcefluid into the member, so that it is injected into the drum between itsends as it rotates during grinding operation of the mill. An adaptationof the invention having those characteristics is that hereafterdescribed.

Members 3|, secured to and extending outwardly from the cylindrical wallof the drum. holds fast thereon an annular wind box 32.

The wind box is substantially a three-wall structure, which is formedwith an outer wall 33, an inner wall 34, and a back wall joining thewalls 33 and 34. It has arcuate openings or ports extendingsubstantially throughout its annulus opposite to back wall 35 betweenplates 36. Those plates are at opposite places on the annulus, and theyare connected to the outer and inner walls 33 and 34.

The rear edge 31 of each plate 36v is curved and recedes from the outerwall 33 to the inner Wall 34, and a partition 38 of correspondingcurvature is joined to the plate at that edge and to those walls anddivides the interior of the box into chambers.

The material of walls 33 and 34 is right turned at their free edges,except at the plates 36, to afford flat concentric arcuate bearingmembers 39 and 40, respectively. These members and plates are arrangedso that their bearing surfaces and the outer surface of the plates arein the same plane. Those surfaces are to form a running seal with partsof a chamber-containing member.

Two diametrically positioned passages 41 extend from a discharge port ofthe wind box to the interior of the drum, first in somewhat radial dis.-position and thence inside. of the drum close to and substantiallyparallel with the lining thereof. Each of these passages is in a member42. That member has a neck 43, which extends into-the drum from the windbox at a place covered by a plate 36 and close to the partition 38, andthe member extends from the neck inside of the drum in approximatelyparallel disposition close to the wall thereof.

Although each member 42 may be in one piece, practically it may be ofblocks 44 and 45 fitted close together at their abutting sides andshaped to be fastened close against the inner side of the drum and fortheir width to displace equivalent lengths of lining plates 25.

Each member 42 has in its passage near the discharge end a rib orprotuberance 46. The side 41 thereof that receives impact of in-fiowingfluid slopes from one wall of the passage to the tip of the rib orprotuberance. Thus the member 42 has a discharge end of nozzle-likeform, with the rib or protuberance 46 restricting the size of thepassage and intensifying the fluid stream emanating therefrom. Moreover,the rib or protuberance prevents grinding bodies and comparatively largeparticles of material being treated from entering the passage in somecircumstances.

An annular non-rotating wind box 48 is associated with the wind box 32.It is the chambercontaining member hereinbefore mentioned. It has anopening at one side that may extend substantially throughout itsannulus, and otherwise is closed by a side wall 39, an outer wall 55,and an inner wall The opening of the box as is alignable with those ofbox 32, when the two boxes are together.

The material of walls 59 and 5! is right turned at their free edges toaiford fiat concentric bearing members or rings 52 and 53, respectively,of

curvature corresponding to that of the bearing members 39 and 40 of therotating box 32. A gasket or seal ring 54 may be interposed between thetwo sets of bearing members.

The non-rotating wind box is kept in close association with the rotatingwind box at their bearing surfaces and prevented from rotation in anysuitable manner.

For example, as shown by the drawing, diametrically positioned radiallydisposed members 55 extend from the non-rotating box. Each of thesemembers extends through plates 56, between which are journaled Wheels orrollers 57. Pillars 58, on opposite sides of the mill, carry tracks 55on which the rollers ride. A cable 60, attached to the plates 55,operates over a pulley-wheel (ii on each of the pillars, and by urge ofweight 62 thereon draws and keeps bearing rings 5253 of the box 48against the bearing rings S d-40 of the box 32. Thus a tight runningsurface joint is maintained at the bearing surfaces of the two boxes.The box 413 is prevented from rotating with the box 32 by the shafts 55resting on the late-roller structure 56-51.

One wind box structure, to this point, has been described. The drawingshows two such structures for separate chambers between which is adivision head 28. Ordinarily, when two wind box structures are used, thenon-rotating boxes face each other; that is, both of them are betweenthe two companion rotating wind boxes. Thus, pull of cables 60 is inopposite directions against the rotating boxes and the drum.Consequently, urge in one direction that might produce undesirable urgeon the drum bearings is counteracted by substantially equal cable urgein the opposite direction.

Air or other fluid is supplied under pressure to the non-rotating windboxes through their intake ports 63 by bifurcated parts 64 of a conduit55 connected with the discharge outlet of a fan driven by a motor 61.

When the drum is rotating in direction of the arrow in Fig. 3, thematerial being treated and the grinding bodies move upwardly with theascending arc of the drum and cascade over to the other side. The heavymass in the drum, during these movements, is subjected to streams of airdischarged thereinto adjacent to the drum wall and thereafter movingtransversely through the mass. These currents operate, between ends ofthe drum, to loosen particles of the material from the grinding bodies,ribs, vanes, division heads, and other elements in the drum, and moreuniformly disperse the material among the grinding bodies.

Altogether, the whirling and swirling action of the laterally andcircumferentially injected air enhances the grinding process, withresults superior to the conventional method of introducing air axiallyat the feed end of the apparatus.

Moreover, injection of air currents into the drum between its feed anddischarge ends operates more effectively to reduce temperature of thecontained mass even to the last division head near the discharge end.Thus, to the place of discharge, the mass is cooled to a greater degreethan by air introduced only at the feed end, which, by the time it hasgone through some of the drum, has become relatively hot.

Mills of the kind with which this invention or dinarily is associatedusually are quite massive, and together with the balls or other grindingbodies and material being treated constitute a ponderous mass.

After drive effort of the operating elements is stopped to discontinuerotation 'of the drum, the contained mass adjacent to the upwardly movedarc of the drum is of such weight as to start oscillation of the drumbefore it comes to a full stop.

During the phases of oscillation opposite to the normal direction ofrotation indicated by the arrow in Fig. 3, some particles of thematerial are apt to enter the rotary wind box through the passage 4! ofthe then backwardly moving member 42 in the then lower portion of thedrum. The passage at the nozzle tip usuall is small enough to prevententrance of grinding bodies, and small grinding bodies and largeparticles of the material are prevented from entering by the restrictingrib 46. The plates 36 keeps matter that has reached the rotary wind boxfrom going into the non-rotary wind box. Further, entrance of matterthrough passage 4| may be retarded by continuing the flowing of fluidinto the drum until oscillation has stopped. When operation of the millis resumed, matter that may have entered the rotary wind box usually isblown back into the drum.

Although the invention has been described as primarily for introductionof air laterally into a rotary grinding drum, it is to be understoodthat it is adaptable for use also in injecting other suitable fluidsinto such mill drums.

Further, it is to be understood the term wind box is used forconvenience to indicate any suitable members coacting as hereinbeforedescribed with other members, and that limitation of the invention touse with gaseous fluid is not intended.

I claim:

A comminuting mill comprising a, rotary drum, a wind box encircling theoutside of and rotating with said drum having a radial face, circularconcentric bearing members on said radial face, said radial face havingan intake opening between said members, a partition dividing theinterior of said box, a plate on said radial face extending between thecircular concentric bearing members adjacent to said partition in thedirection of I 5 rotation, there being a passage extending from a partof said box adjacent to said plate to the interior of said drum, anon-rotating wind box, annular bearing members thereon in contact withthose of said rotating box, there being an opening from saidnon-rotating box between its bearin members alignable with the openingof said rotating box, means holding said bearing members in contact, andmeans to force fluid into said nonrotating box, v

HAAVARD KRONSTAD.

REFERENCES CITED The following references are of record in the file 01this patent:

Number Number UNITED STATES PATENTS Name Date Pomeroy July 18, 1922Hopwood Nov. 10, 1925 Newhouse Mar. 15, 1927 Bojner et a1 Apr. 16, 1929Vanderwerp Oct. 11, 1938 FOREIGN PATENTS Country Date Great Britain Mar.18, 1926

